The present invention relates to electronic seals generally and more particularly to tamper-resistant electronic seals.
The following U.S. Patents are believed to be representative of the prior art:
U.S. Pat. Nos. 4,750,197, 5,056,837; 5,097,253, 5,127,687; 5,169,188; 5,189,396; 5,406,263, 5,421,177, 5,587,702; 5,656,996 and 6,069,563.
The present invention seeks to provide an improved electronic seal
There is thus provided in accordance with a preferred embodiment of the present invention a tamper-resistant remotely monitorable electronic seal including a shaft portion, a socket arranged to engage the shaft portion in a monitorable manner, whereby disengagement of the socket and the shaft portion results in a monitorable event, and a wireless communicator associated with at least one of the shaft portion and the socket and being operative to provide a remotely monitorable indication of the monitorable event. Preferably, the wireless communicator is a transceiver. Additionally, the shaft portion includes at least one conductive path which is interrupted in response to disengagement of the socket and the shaft portion and wherein the wireless communicator is operative to provide a remotely monitorable indication of the monitorable event.
In accordance with another preferred embodiment of the present invention, the shaft portion includes a frangible shaft portion having a press-fit tip, the socket includes a press-fit socket arranged to engage the press-fit tip in a destructably removable manner, whereby disengagement of the socket and the shaft portion results in breakage of the shaft portion, the at least one conductive path extends at least through the shaft portion and is breakable in response to breakage of the shaft portion, and the wireless communicator is associated with at least one of the shaft portion and the press-fit socket and is operative to provide a remotely monitorable indication of the integrity or lack of integrity of the at least one conductive path. Preferably, the at least one conductive path is defined by conductors extending through the shaft portion which are in electrical contact with a conductor formed in the press-fit socket when the shaft portion and the socket are in press-fit engagement. Additionally, the press-fit tip includes a toothed tip. Alternatively, the at least one conductive path includes at least one reed switch which is operated by a magnet associated with the socket whereby when the shaft portion is separated from the socket for any reason, the at least one conductive path is broken.
In accordance with yet another preferred embodiment of the present invention, the shaft portion includes a frangible shaft portion having a lockable portion, the socket includes a locking element arranged to engage the lockable portion in a destructably removable manner, whereby disengagement of the locking element and the shaft portion results in breakage of the shaft portion, the at least one conductive path extends at least through the shaft portion and is breakable in response to breakage of the shaft portion, and the wireless communicator is associated with at least one of the shaft portion and the socket and is operative to provide a remotely monitorable indication of the integrity or lack of integrity of the at least one conductive path. Preferably, the shaft portion includes a groove adaptable for lockable engagement with the locking element. Additionally, the at least one conductive path includes at least one reed switch which is operated by a magnet associated with the socket whereby when the shaft portion is separated from the socket for any reason, the at least one conductive path is broken.
In accordance with a further preferred embodiment of the present invention, the communicator is located in a sensing circuitry and communicator housing integrally formed with the shaft portion. Preferably, the frangible shaft portion includes at least one frangible location having relatively weak mechanical strength as compared with other portions of the shaft portion.